Cellular Angiofibroma With Atypia or Sarcomatous Transformation: Clinicopathologic Analysis of 13 Cases

Cellular angiofibroma of the female pelvic cavity: a case report

BACKGROUND

Cellular angiofibroma is a rare benign mesenchymal tumor that mostly occurs in the genital area. Its occurrence outside this region, particularly in the pelvis, is extremely rare. To our knowledge, this study reports the first case of cellular angiofibroma occurring in the pelvic cavity, except for one case reported in the retroperitoneum.

CASE PRESENTATION

A 25-year-old female patient with chronic, intermittent, dull pain in the lower abdomen that lasted for several months was referred to our clinic. Imaging studies revealed a tumor in the pelvic cavity anterior to the bladder. The radiographic characteristics of this tumor indicated a hypervascular nature, suggesting the possibility of a pheochromocytoma or a neuroendocrine tumor. The patient underwent surgical excision of the lesion. To date, no recurrence has been observed four months after excision.

CONCLUSIONS

Cellular angiofibroma, although rare in the pelvic cavity, should be considered in the differential diagnosis of hypervascular pelvic space-occupying lesions. Immunohistochemical staining can help confirm the diagnosis of this condition. Treatment is generally straightforward, involving local excision of the tumor followed by postoperative monitoring.

Pseudoangiomatous Spindle Cell Lipoma: A Rare and Distinct Pattern of Lipomatous Tumors

Pseudoangiomatous spindle cell lipoma is a rare pattern within the spindle cell lipoma spectrum that exhibits a remarkable histological pattern characterized by its resemblance to vascular lesions, creating a pseudoangiomatous appearance. Approximately 20 to 30 reports have been described in the literature. In this context, we present an intriguing report of pseudoangiomatous spindle cell lipoma showcasing a unique low-fat pseudo angiomatous pattern in a 61-year-old male patient presented with a 6-cm subcutaneous mass on his right arm, which was thoroughly investigated and subsequently excised. Microscopic examination revealed bland spindle cells infiltrates within a fibromyxoid stroma. Notably, the tumor exhibited distinctive branching and dilated vascular-like spaces that formed pseudopapillary (villiform) projections. Interestingly, the tumor displayed certain regions featuring mature adipose tissue components, alongside hyalinized blood vessels. No necrosis, atypical spindle cells, increased mitotic activity, or pleomorphic lipoblasts were observed. The immunohistochemical evaluation demonstrated diffuse positive staining for CD34 and negative staining for STAT6. This report of a low-fat pattern of pseudoangiomatous spindle cell lipoma underscores the importance of recognizing and characterizing rare entity subtype for accurate diagnosis and appropriate management. This report contributes to the expanding understanding of the diverse presentations of pseudo angiomatous spindle cell lipomas and underscores the significance of comprehensive histopathological assessment.

Atypical Spindle Cell/Pleomorphic Lipomatous Tumor With Sarcomatous Transformation: Clinicopathologic and Molecular Analysis of 4 Cases

Atypical spindle cell/pleomorphic lipomatous tumor (ASPLT) is a recently described adipocytic tumor predominantly affecting the subcutaneous soft tissues of adults. Previous studies have shown that ASPLT follows a benign clinical course with a 4% to 12% local recurrence rate and no risk of dedifferentiation. Herein, we describe the clinicopathologic and molecular findings of 4 cases of ASPLT showing unequivocal sarcomatous transformation. Three patients were male and one was female, aged 65, 70, 74, and 78 years. Two cases presented as mass-forming lesions, while 1 case was incidentally discovered. The tumors measured 30, 55, 80, and 110 mm and occurred in the chest wall (n = 2) or arm (n = 2); all were subcutaneous. Microscopically, they showed a biphasic appearance comprising a low-grade ASPLT component and a high-grade sarcomatous component. The low-grade components showed features in the spectrum of either atypical pleomorphic lipomatous tumor (n = 2) or atypical spindle cell lipomatous tumor (n = 2). The high-grade components displayed leiomyosarcoma-like (n = 2), pleomorphic liposarcoma-like (n = 1) or undifferentiated sarcoma-like (n = 1) morphology. On immunohistochemistry, tumors were negative for MDM2 and showed loss of RB1 expression. In addition, the leiomyosarcoma-like areas seen in 2 cases were positive for smooth muscle actin and H-caldesmon. Single-nucleotide polymorphism array, performed in 3 cases, showed deletions of TP53, RB1, and flanking genes in both components. In contrast, the sarcomatous components showed more complex genomic profiles with rare segmental gains and recurrent loss of PTEN (n = 3), ATM (n = 2), and CDKN2A/B (n = 2) among other genes. Whole exome sequencing identified a TP53 variant in one case and an ATRX variant in another, each occurring in both tumor components. Limited clinical follow-up showed no recurrence or metastasis after 1 to 13 months (median, 7.5 months) postsurgical excision. Altogether, our data support that ASPLT can rarely develop sarcomatous transformation and offer insights into the molecular mechanisms underlying this event.

SMARCB1/INI1-deficient epithelioid and myxoid neoplasms in paratesticular region: Expanding the clinicopathologic and molecular spectrum

SMARCB1/INI1-deficient soft tissue tumors with epithelioid and myxoid features are diverse and mainly include soft tissue myoepithelial tumor, extraskeletal myxoid chondrosarcoma, and the recently described myoepithelioma-like tumor of the vulvar region and myxoepithelioid tumor with chordoid features. Because of their overlapping features, the accurate diagnosis and classification of these tumors are often challenging. Herein, we report two unique cases of SMARCB1/INI1-deficient soft tissue neoplasm with epithelioid and myxoid features occurring in male paratesticular region. The first case was a 52-year-old man presented with an intermittent painful left paratesticular mass for 1 year. The second case was a 41-year-old man presented with a painless paratesticular mass on the right side for 3 months. Both patients underwent an orchiectomy. After 6 and 26 months of follow-up, both were alive with no evidence of recurrence or metastasis. In both cases, the tumor was relatively well-demarcated and showed monomorphic round to epithelioid cells arranged in a nested, trabecular, reticular, and corded pattern, setting in a myxohyalinized and vascularized matrix. The tumor cells showed relatively uniform round nuclei with vesicular chromatin and variably prominent nucleoli. No rhabdoid cells were identified. Mitoses numbered 3 and 2 per 10 high-power fields. Tumor necrosis or lymphovascular invasion was absent. Immunohistochemically, both tumors expressed epithelial membrane antigen (focal), calponin (focal), and CD99. SMARCB1/INI1 expression was deficient in both cases. In addition, case 1 diffusely expressed pan-cytokeratin, and case 2 diffusely expressed CD34 and synaptophysin. Molecular genetically, case 1 showed SMARCB1 homozygous deletion as detected by fluorescence in-situ hybridization (FISH), and case 2 demonstrated SMARCB1 copy number deletions by next-generation sequencing and SMARCB1 monoallelic deletion by FISH. Both cases lacked EWSR1 rearrangements by FISH. The overall clinicopathologic profiles of the two cases made it difficult to classify them as one of the established categories of SMARCB1/INI1-deficient mesenchymal tumors. Our study further expands the clinicopathologic and molecular spectrum of SMARCB1/INI1-deficient epithelioid and myxoid neoplasms and highlights the challenges to diagnose these tumors.

Subcutaneous cellular angiofibroma of arm: A case report

ABSTRACT

Cellular angiofibroma is a rare benign mesenchymal tumor reported in genital region in middle-aged patients. We report a rare presentation of the tumor in an extragenital location-the arm of a young male patient. After biopsy, an en bloc excision of the mass was done and diagnosis was confirmed. No adjuvant treatment was required. Our patient had an unusual location for this rare tumor at an age younger than reported in literature so far. Imaging can only predict the mesenchymal nature of the tumor but histopathology and immunohistochemistry (IHC) is the cornerstone of diagnosis. Cellular angiofibroma has a good prognosis. Histopathology and IHC are needed to confirm the diagnosis, hence emphasizing the role of a good and experienced pathologist. The pathogenesis of the cellular angiofibroma is still not fully determined and current hormonal and immunotherapy suppression regimes will need further evaluation.

Paratesticular Cellular Angiofibroma (CAF): A Rare Case Report

Cellular angiofibromas (CAFs) are infrequent and benign soft-tissue tumors that primarily affect the genitourinary region in both genders. The authors report the case of a 71-year-old male patient who exhibited progressively increasing swelling in both testicles, with greater prominence noted on the left side. Initial findings from physical examination and scrotal ultrasound indicated the possibility of bilateral hydrocele, so the patient was recommended surgical intervention of the left more prominent side. Intraoperatively, a left paratesticular mass was identified and subsequently excised. Histopathological analysis confirmed the diagnosis of cellular angiofibroma. Surgeons should be cognizant of this tumor type to optimize treatment strategies, as local excision demonstrates a potential to preserve the testicle and yield favorable outcomes. Although occurrences of local recurrence are extremely rare, long-term follow-up is imperative.

Combination of high-frequency electric with 5-ALA photodynamic therapy in cellular angiofibroma of vulva: A case report

Cellular angiofibroma is a rare benign tumor and difficult to diagnose. Surgery was used in most cases of prior treatment. However, due to the individual differences, this method may be limited, and there is a risk of recurrence. After signing informed consent for treatment, we treated an 18-year-old female with cellular angiofibroma successfully by using the High-Frequency electric pretreatment combined with 5-Aminolevulinic Acid (5-ALA) photodynamic therapy. The tumor was numerous and irregularly shaped on the right labia majora. The specific treatment process was as follows:5-Aminolevulinic Acid (5-ALA) photodynamic therapy was administered after pretreatment with high-frequency electric ion. We did five treatments in total, 10 days apart. And the therapeutic effect was satisfactory for patients. The wound healed well and no recurrence during 12 months follow-up, and the follow-up is continuing. For similar cases, our experience can be taken into account.

Surgical excision of giant vulvar angiofibroma: A case report and a review of literature

RATIONALE

Cellular angiofibroma (CA) is a rare tumor of the soft tissue classified as a benign fibroblastic/myofibroblastic tumor. Considering this, the literature regarding CA mainly, but not exclusively, comprises single case reports and case series. Here, we report a case of giant CA of the vulva with comprehensive literature review.

PATIENT CONCERNS

We present a case of a massive vulvar CA arising in 53-year-old woman with no notable medical or surgical history. The mass has grown considerably over time, causing pain and difficult urination, defecation, and movement. The patient had normal regular menstrual cycle with no previous contraception use. Vaginal examination exposed a right-sided large tender vulvar mass with normal-looking vagina.

DIAGNOSES

Pelvic magnetic resonance imaging with contrast revealed a large right vulvar heterogeneously enhancing soft tissue mass measuring 13.1 × 10.9 × 10.7 cm expending the left vulva, with internal and peripheral voids resembling feeding vessels. The mass was surgically removed, and subsequent histopathology showed skin-covered dermal-based lesion composed of fibroblast-like bland and spindle cell proliferation with thin-walled blood vessels of various sizes. Immunohistostaining of CD34 and smooth muscle antigen were both positive, while desmin was found to be negative. A diagnosis of vulvar angiofibroma was made based on the clinical scenario, imaging, and histopathology.

INTERVENTIONS

Mass vulvectomy was performed starting with a circumferential incision at the base of the mass and structural dissection to separate the mass from the vulvar wall. The incision was successfully closed, and subcuticular stitches were applied to the skin.

OUTCOMES

The patient's complaints were significantly relieved with no postoperative complications and the patient is being followed regularly in an outpatient setting.

LESSONS

Due to its extremely benign nature of CA, and the implausible ability of its recurrence, it was decided to surgically excise it. Despite its rarity, it can be readily identified at its earlier stages preventing the vexing and exasperating symptoms accompanied with increased size as mentioned.

Update on Mesenchymal Lesions of the Lower Female Genital Tract

This article provides an update of the recent developments in mesenchymal tumors of lower genital tract. We focus on the characterization of recurrent molecular events in certain genital stromal tumors, for instance angiomyofibroblastomas and superficial myofibroblastomas. Moreover, fusions involving Tyrosine-kinases receptors (NTRK, FRFR1, RET, COL1A1-PDGFB) have been demonstrated in an emerging group of mesenchymal tumors characterized by a fibrosarcoma-like morphology and a predilection for uterine cervix of premenopausal women. We also cover the topic of smooth muscle tumors of the lower genital tract, which can be now classified using the same diagnostic criteria than their uterine counterpart..

Atypical Spindle Cell/Pleomorphic Lipomatous Tumor with Pleomorphic Hyalinizing Angiectatic Tumor-Like Growth Pattern: A Search for Diagnostic Clues

Atypical spindle cell/pleomorphic lipomatous tumor (ASPLT) is a newly described adipocytic tumor type, recently included as a separate tumor entity in the fifth edition of the World Health Organization (WHO) classification of soft tissue and bone tumors. Here, we describe a case of an ASPLT with a striking pleomorphic hyalinizing angiectatic tumor (PHAT)-like growth pattern and discuss the diagnostical clues, which led to the diagnosis of ASPLT. To our knowledge, a PHAT-like growth pattern has not yet been reported in the setting of ASPLT.

Angiomyofibroblastoma and Potential Mimicking Soft Tissue Tumors That May Occasionally Present in the Retroperitoneum: An Approach to the Differential Diagnosis With Report of an Unusual Index Case Abutting the Kidney

The retroperitoneal soft tissues, extending from the pelvic floor to the level of the diaphragm, are the source of a variety of mesenchymal neoplasms with overlapping features and distinct clinical behaviors, making their distinction of crucial importance. Herein, we report a rare retroperitoneal angiomyofibroblastoma (AMFB) that presented as a right abdominal mass in a 25-year-old woman and that clinically simulated a primary renal carcinoma. The patient underwent complete surgical resection showing a well-circumscribed tumor adjacent to but separate from the right kidney. It was comprised of irregular, often anastomosing islands and cords of plump to spindled cells in a collagenous stroma with numerous thin-walled vessels. The tumor cells clustered around the vessels and admixed with moderate numbers of adipocytes. There was neither significant nuclear atypia nor mitotic activity. Immunohistochemically, the tumor cells showed strong reactivity for desmin, diffuse expression of estrogen and progesterone receptors, retained nuclear expression of retinoblastoma protein, and absent CD34 expression. The immunomorphological features were these of a "lipomatous variant" of AMFB of the retroperitoneum. The occurrence of AMFB in the retroperitoneum is unexpected since it mostly develops in the lower genital tract of young women, making its recognition in this rare location difficult. As a consequence, more common pelvic or retroperitoneal soft tissue neoplasms may represent the primary diagnostic considerations. We, therefore, review a variety of soft tissue tumors occurring in the pelvis/retroperitoneum that, to some degree, may mimic AMFB, and present key findings to assist in accurate diagnosis.

Histopathologic and Genetic Findings in Atypical Spindle Cell/Pleomorphic Lipomatous Tumors and Atypical Pleomorphic Fibromas

BACKGROUND

Spindle cell lipomas, pleomorphic lipomas (SCL/PLs) and pleomorphic fibromas (PF) are tumors with loss of retinoblastoma (RB). The latest World Health Organization classification includes a category of atypical spindle cell/pleomorphic lipomatous tumors (ASPLT) that encompasses tumors in this spectrum that show atypical histopathologic features. We have observed PFs that show similar atypical features.

METHODS

Cases of SCL/PL and PF with atypical features were collected from tissue archives between 2010-2019. Genetic alterations were investigated using array comparative genomic hybridization (aCGH).

RESULT

Of 15 cases found, most tumors were dermal-based with fibrocytic or fibroadipocytic appearance and occasional lipoblasts. All cases had a high proliferation index with atypical mitotic figures in 71% of cases. Chromosome 13q loss was present in all cases with CGH data. Additional recurrent chromosomal losses included 17p, 16q, 17q, 20p, 4, and 10. No recurrence was found in limited follow up.

CONCLUSIONS

ASPLTs are characterized by loss of RB, prominent nuclear pleomorphism, mitotic activity including atypical mitotic figures, and genomic instability with multiple chromosomal aberrations. A similar group of tumors with these histopathologic features lacks lipomatous differentiation, and we propose the diagnosis of atypical PF as a fibromatous variant of ASPLT. Limited clinical follow up appears benign.

Practical Approach to the Diagnosis of the Vulvo-Vaginal Stromal Tumors: An Overview

Background: The category of the “stromal tumors of the lower female genital tract” encompasses a wide spectrum of lesions with variable heterogeneity, which can be nosologically classified on the basis of their morphologic and immunohistochemical profiles as deep (aggressive) angiomyxoma (DAM), cellular angiofibroma (CAF), angiomyofibroblastoma (AMFB) or myofibroblastoma (MFB). Despite the differential diagnosis between these entities being usually straightforward, their increasingly recognized unusual morphological variants, along with the overlapping morphological and immunohistochemical features among these tumours, may raise serious differential diagnostic problems. Methods and Results: The data presented in the present paper have been retrieved from the entire published literature on the PubMed website about DAM, CAF, AFMB and MFB from 1984 to 2021. The selected articles are mainly represented by small-series, and, more rarely, single-case reports with unusual clinicopathologic features. The present review focuses on the diagnostic clues of the stromal tumours of the lower female genital tract to achieve a correct classification. The main clinicopathologic features of each single entity, emphasizing their differential diagnostic clues, are discussed and summarized in tables. Representative illustrations, including the unusual morphological variants, of each single tumour are also provided. Conclusion: Awareness by pathologists of the wide morphological and immunohistochemical spectrum exhibited by these tumours is crucial to achieve correct diagnoses and to avoid confusion with reactive conditions or other benign or malignant entities.

Cellular angiofibroma arising in the anorectal region: clinicopathologic and immunohistochemical analysis of five cases

Cellular angiofibroma (CA) is a rare, benign mesenchymal tumor with a predilection to the distal female and male genital tract. Extragenital examples of CA, including anorectal CAs, are exceedingly rare and documented mainly as single case reports. Herein, we analyze the clinicopathological and immunohistochemical features of 5 anorectal CAs. There were 4 males and one female ranging in age from 45 to 70 (median, 58) years at the time of surgery. Tumors arose in the superficial tissues of the anorectal (n = 3) and perianal (n = 2) regions. The tumors were well circumscribed ranging from 2 to 6.7 (median, 5.4) cm. All demonstrated a low to moderately cellular proliferation of cytologically bland spindled cells within a variably dense collagenous and focally myxocollagenous stroma and small- to medium-sized vessels featuring perivascular collagen deposition. Two cases showed degenerative and/or inflammatory changes. All 5 tumors strongly expressed CD34 and androgen receptor proteins, more variably expressed estrogen (n = 5) and progesterone (n = 4) receptor proteins and desmin (n = 3), and focally expressed alpha-smooth muscle actin (n = 3), GATA-3 (n = 2), and p16 (n = 1). Retinoblastoma protein expression was reduced (n = 4) (compared with expression in endothelial cells) or completely lost (n = 1). All patients were treated with simple surgical excision, and the 2 study members with follow-up data showed no evidence of local recurrence over a postoperative follow-up interval of 23 and 73 months. In comparison with conventional genital tract CA, our 5 anorectal CAs occurred mostly in males, were generally less cellular, and appear to follow a similar uneventful clinical course.

Re-evaluating tumors of purported specialized prostatic stromal origin reveals molecular heterogeneity, including non-recurring gene fusions characteristic of uterine and soft tissue sarcoma subtypes

Tumors of purported specialized prostatic stromal origin comprise prostatic stromal sarcomas (PSS) and stromal tumors of uncertain malignant potential (STUMP). Prior studies have described their clinicopathologic characteristics, but the molecular features remain incompletely understood. Moreover, these neoplasms are morphologically heterogeneous and the lack of specific adjunctive markers of prostatic stromal lineage make precise definition more difficult, leading some to question whether they represent a specific tumor type. In this study, we used next-generation DNA and RNA sequencing to profile 25 primary prostatic mesenchymal neoplasms of possible specialized prostatic stromal origin, including cases originally diagnosed as PSS (11) and STUMP (14). Morphologically, the series comprised 20 cases with solid architecture (11 PSS and 9 STUMP) and 5 cases with phyllodes-like growth pattern (all STUMP). Combined DNA and RNA sequencing results demonstrated that 19/22 (86%) cases that underwent successful sequencing (either DNA or RNA) harbored pathogenic somatic variants. Except for TP53 alterations (6 cases), ATRX mutations (2 cases), and a few copy number variants (-13q, -14q, -16q and +8/8p), the findings were largely nonrecurrent. Eight gene rearrangements were found, and 4 (NAB2-STAT6, JAZF1-SUZ12, TPM3-NTRK1 and BCOR-MAML3) were useful for reclassification of the cases as specific entities. The present study shows that mesenchymal neoplasms of the prostate are morphologically and molecularly heterogeneous and include neoplasms that harbor genetic aberrations seen in specific mesenchymal tumors arising in other anatomic sites, including soft tissue and the uterus. These data suggest that tumors of purported specialized prostatic stromal origin may perhaps not represent a single diagnostic entity or specific disease group and that alternative diagnoses should be carefully considered.

The Rapidly Expanding Group of RB1-Deleted Soft Tissue Tumors: An Updated Review

The classification of soft tissue tumors has evolved considerably in the last decade, largely due to advances in understanding the pathogenetic basis of many of these, sometimes rare, tumors. Deletion of Retinoblastoma 1 (RB1), a well-known tumor suppressor gene, has been implicated in the tumorigenesis of a particular group of soft tissue neoplasms. This group of so-called “RB1-deleted soft tissue tumors” has been rapidly expanding in recent years, currently consisting of spindle cell/pleomorphic lipoma, atypical spindle cell/pleomorphic lipomatous tumor, pleomorphic liposarcoma, myofibroblastoma, cellular angiofibroma, and acral fibromyxoma. Most of these neoplasms, except pleomorphic liposarcoma, are considered benign entities and are mainly described in the older adult population. This article will review the currently known morphological, immunohistochemical, and molecular features of this heterogeneous group of mesenchymal tumors with an emphasis on differential diagnosis.

Transperineal excision of a sizeable angiofibroma of the ischiorectal fossa. A case report

Cellular angiofibroma is a recently described rare benign soft-tissue tumor more commonly presenting in middle-aged women, often mimicking malignancy. The vulva is most common location. Complete local excision is the best curative treatment and usually there is no recurrence after surgery. We describe a 49-year-old woman with a painless tumor in the left ischiorectal fossa. It was a random finding in a routine computed tomography (CT) scan after resection of ear melanoma 3 years previously. Ultrasonography showed a solid mass, and further magnetic resonance imaging (MRI) suggested a rhabdomyosarcoma. Altogether, these findings indicated malignant disease. An uncomplicated simple excision of the tumor was done in the operating theatre. The mass measured 7×5×5 cm and the histopathological examination found that it was a cellular angiofibroma, a benign lesion. There were no postoperative complications. This case report highlights the need for multidisciplinary team management of rare tumors such as cellular angiofibromas.

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Soft tissue angiofibromas are benign, fibrovascular tumors with average size <3 cm that can occasionally be localized in the genital area.

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The vulva is the most common genital location.

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This report describes the management of an exceptionally large angiofibroma of the perineum in a 49-years-old woman with a history of melanoma.

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Minimally invasive transperineal excision was successfully performed by a gynecologist and a general surgeon.

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Joint multidisciplinary approach involving gynecologists, colo-rectal surgeons, radiologists, and pathologists, is necessary for management.

Cellular Angiofibroma Presenting as a Subepithelial Rectal Mass

A very rare case of cellular angiofibroma arising from the rectum in a 62-year-old man with a normal colonoscopy 2 years earlier is reported. To our knowledge, this is the first such case reported in the literature. The tumor was transanally excised with clear margins, and the patient had no postoperative complications. It is key to accurately differentiate this lesion from other subepithelial rectal tumors and more aggressive genital soft tissue tumors because clinical management varies. We performed a review of clinical records and pathology as well as an extensive literature review.

Cellular angiofibroma of orbit- a rare tumor at the rarest location

Cellular angiofibroma (CAF) is a rare, site-specific benign tumor of mesenchymal origin, which is exclusive of the genital region except very few reported cases of extragenital CAF. Very recently the first case report of orbital CAF has been published and we are presenting the second documented case of CAF in this unusual location, in a 37-year-old man. Magnetic resonance imaging with T2 weighted image revealed a hyper-intense globular mass in the superomedial extraconal region of the left orbit. Histopathology of the excised mass showed numerous bland spindle cells embedded in wispy collagen, suggesting spindle cell tumor. On immunohistochemistry, the specimen was strongly positive to CD34 but negative to desmin, SMA, S-100, C-kit, ERG, EMG, CD31, and CD63, that further confirmed the diagnosis of CAF. CAF is a rare mesenchymal tumor and to the best of the authors' knowledge, this would be the second documented case of orbital CAF.

Mesenchymal lesions of the vulva

Mesenchymal lesions of the vulva include site-specific entities limited to the lower genital tract, as well as a range of non-site-specific tumors that are more common at extragenital sites. Site-specific lesions include fibroepithelial stromal polyp, cellular angiofibroma, angiomyofibroblastoma, and aggressive angiomyxoma. Non-site-specific tumors that may occur in the vulva include those of smooth muscle, skeletal muscle, vascular, neural, adipocytic, and uncertain differentiation. This review discusses both site-specific and non-site-specific vulvar mesenchymal lesions including non-neoplastic proliferations, benign neoplasms, locally aggressive neoplasms with a predilection for local recurrence, neoplasms of indeterminate biologic potential, and frankly malignant neoplasms with a high risk of distant metastasis and death. Accurate diagnosis is essential for proper management, and is facilitated by correlation with clinical findings and targeted application of immunohistochemical and molecular studies.

A Novel Case of Mammary-Type Myofibroblastoma With Sarcomatous Features

Mammary-type myofibroblastoma (MFB) is a benign spindle cell tumor of the breast and soft tissue characterized by 13q14 alterations leading to loss of Rb-1 protein expression, a feature shared among spindle cell lipoma and cellular angiofibroma. In this article, we present a novel case of MFB arising in the left breast of a 70-year old man that microscopically showed an abrupt transition from classic MFB morphology to an area with cytologic atypia and mitotic activity, akin to sarcomatous transformation described in cellular angiofibromas. A thorough workup of the molecular underpinnings of both components using chromosomal microarray and next-generation sequencing platforms supported a clonal relationship. Nearly identical copy number changes, including a single copy loss of 13q14, were found in both components; in addition, the sarcomatous component harbored biallelic TP53 alterations. It is important for pathologists to recognize that sarcomatous features can occur in mammary-type MFB to arrive at the correct diagnosis.

Cervicovaginal cellular angiofibroma

Cellular angiofibroma is a rare type of benign mesenchymal tumour that arises mostly in middle-aged women. It needs to be distinguished from other neoplasms and has a predilection for the vulvovaginal region. To our knowledge, this is the first case of a cervical cellular angiofibroma. A 34-year-old nulligravid woman was referred with a large mass bulging in the fornix posterior. Ultrasound scanning and MRI showed a large solid mass projecting in the pouch of Douglas. Laparoscopic surgical excision was performed. Histopathological examination showed a well-demarcated, unencapsulated tumour, consisting of short fascicles of spindle cells in-between thick-walled medium-sized vessels. On immunohistochemistry, there was strong reactivity with antibodies against CD34 and oestrogen receptor. Angiofibromas are benign mesenchymal tumours mostly occurring in middle-aged women. They can cause abnormal swelling and uterine bleeding and need to be distinguished from other (malignant) neoplasms.

Successful resection of cellular angiofibroma in the retroperitoneum by using laparoscopic approach

Retroperitoneal cellular angiofibroma (RCA) is very rare, and the optimal treatment for RCA has not been established. We report the case of RCA in a 58-year-old man who underwent curative laparoscopy-assisted resection. Preoperative computed tomography showed heterogeneous enhancement of the 7 cm diameter tumor in the pelvis. A smaller (2.3 cm) mass was also detected in the small intestine. The preoperative diagnosis was peritoneal metastasis of the gastrointestinal tumor of the small intestine. The pelvic tumor was laparoscopically mobilized from the rectum, the left ureter, and the left internal iliac vessels. The tumor was excised by detachment from the urinary bladder in laparotomy. The pathological diagnosis was RCA. The tumor had not recurred by the 1-year follow-up. The laparoscopic approach thus might be useful for resection of RCA.

Cellular angiofibroma of the orbit

Cellular angiofibroma is a benign mesenchymal tumor most commonly located in the distal genital tract of both men and women. Although extragenital locations have been reported rarely, this is the first report of cellular angiofibroma of the orbit. A 58-year-old man presented with a mass in the left superomedial orbit since 2 years. Magnetic resonance imaging showed a well-demarcated lesion with a homogeneous intermediate signal intensity on both T1- and T2-weighted images, homogeneous contrast enhancement and high signal intensity on diffusion-weighted images. Complete excision was performed through a medial upper eyelid crease incision. Histopathology showed a vascular CD34-positive and STAT6-negative spindle cell tumor with monoallelic loss of FOXO1, indicating cellular angiofibroma.

First Glance of Molecular Profile of Atypical Cellular Angiofibroma/Cellular Angiofibroma with Sarcomatous Transformation by Next Generation Sequencing

Cellular angiofibroma is a rare benign mesenchymal neoplasm most commonly occurring in the vulvovaginal region in women and the inguinoscrotal region in men with specific genetic deletion involved in the RB1 gene in chromosome 13q14 region. Atypical cellular angiofibroma and cellular angiofibroma with sarcomatous transformation are recently described variants showing worrisome morphological features and strong, diffuse p16 expression. Nevertheless, the molecular profile of these tumor entities is largely unknown. We carried out a next generation sequencing (NGS) study from six cases of atypical cellular angiofibroma and cellular angiofibroma with sarcomatous transformation. We were able to identify oncogenic TP53 gene mutations (33%) which may contribute to pathogenesis also resulting in p16 overexpression. In addition, RB1 gene alterations generally present were identified. Since it is a recently described and rare entity, the whole molecular signaling pathway is still largely obscured and the analysis of larger cohorts is needed to elucidate this issue.

Cellular angiofibroma in the hypopharynx: A case report

RATIONALE

Cellular angiofibroma is a rare benign mesenchymal tumor which mostly occurs in the superficial soft tissues of the genital region. Occurrence in the head and neck region is extremely rare. To our knowledge, this is the first case of cellular angiofibroma arising in the hypopharynx.

PATIENT'S CONCERNS

A 54-year-old male complained of a mass moving through his throat for 1 month. A tumor was found in the right lateral wall of the pharyngeal at the level of the epiglottis by laryngoscope. Magnetic resonance imaging confirmed the presence of a mass in the right lateral pharyngeal area. A benign tumor was suspected based on the clinical symptoms and imaging findings.

DIAGNOSIS

A supporting laryngoscope was performed under general anesthesia and the lesion was resected. Immunohistochemical analysis revealed cellular angiofibroma.

INTERVENTIONS

The patient underwent surgical excision of the lesion.

OUTCOMES

Thus far, no recurrence has been observed 6 months after excision.

LESSONS

Cellular angiofibroma located in the lateral pharyngeal is rare; however, immunohistochemical staining is helpful for its diagnosis. Treatment is relatively simple and requires local excision and follow-up.

The expanding morphological and genetic spectrum of MYOD1-mutant spindle cell/sclerosing rhabdomyosarcomas: a clinicopathological and molecular comparison of mutated and non-mutated cases

AIMS

Spindle cell/sclerosing rhabdomyosarcomas (SC/SRMS) feature spindled and/or rounded rhabdomyosarcomatous cells within variably hyalinised stroma. Only 30-67% of SC/SRMSs harbour neomorphic MYOD1 p.L122R mutations, indicating heterogeneity in this RMS type. We compared MYOD1-mutant and non-mutant cases to characterise the histological and genetic spectrum of mutated SC/SRMS.

METHODS AND RESULTS

Seventeen RMSs with spindled, sclerosing or hybrid histology were sequenced to identify MYOD1 and PIK3CA mutations and reappraised to assess histological features and myogenic immunophenotypes. Twelve SC/SRMSs harboured MYOD1 mutations, including homozygous p.L122R (n = 8), heterozygous p.L122R (n = 3) and heterozygous p.E118K (n = 1). MYOD1-mutant tumours affected nine females and three males aged 8-64 years (median = 22.5), had a median size of 4.2 cm (range = 2-22) and involved the head and neck (n = 7), extremities (n = 4) and mediastinum (n = 1). Fascicular/spindle histology was predominant in four cases, including one with heterologous lipoblasts in focally myxoid stroma. Four sclerosing cases mainly comprised rounded cells, including one with multinucleated tumour cells. Four cases were histologically hybrid. The only PIK3CA (p.H1047R) mutation was detected in a predominantly spindled MYOD1-p.L122R-mutated case, but not in its laser-microdissected lipoblast-containing area. All MYOD1-mutant cases exhibited diffuse MYOD1 expression but patchy myogenin reactivity. At final follow-up (median = 13.5 months), recurrences (n = 4), metastases (n = 2) or both (n = 1) occurred in seven MYOD1-mutant cases; one had died of disease. Five non-mutated cases were reclassified as spindle embryonal (n = 3), dense embryonal (n = 1) and unclassifiable (n = 1) RMSs.

CONCLUSION

MYOD1-mutant RMSs are uncommonly mutated with PIK3CA and behave aggressively with an expanded morphological and genetic spectrum, including lipoblastic differentiation, multinucleated cells and the alternative p.E118K mutation.

Refinements in Sarcoma Classification in the Current 2013 World Health Organization Classification of Tumours of Soft Tissue and Bone

The fourth edition of the World Health Organization (WHO) Classification of Tumours of Soft Tissue and Bone was published in February 2013. The 2013 WHO volume provides an updated classification scheme and reproducible diagnostic criteria, which are based on recent clinicopathologic studies and genetic and molecular data that facilitated refined definition of established tumor types, recognition of novel entities, and the development of novel diagnostic markers. This article reviews updates and changes in the classification of bone and soft tissue tumors from the 2002 volume.

A Giant Vulvar Mass: A Case Study of Cellular Angiofibroma

Cellular angiofibroma is a mesenchymal tumor that affects both genders. Nucci et al. first described it in 1997. Cellular angiofibroma is generally a small and asymptomatic mass that primarily arises in the vulvar-vaginal region, although rare cases have been reported in the pelvic and extrapelvic regions. It affects women most often during the fifth decade of life. The treatment requires simple local excision due to low local recurrence and no chance of metastasization. The current study presents a case of angiofibroma in the vulvar region that measured approximately 20 cm.

Cellular angiofibroma of the vulva: a poorly known entity, a case report and literature review

BACKGROUND

Cellular angiofibroma represents a newly described, site specific tumor. Histologically, CAF is a benign mesenchymal neoplasm characterized by two principal components: bland spindle cells and prominent small to medium-sized vessels with mural hyalinization. The indolent nature of the lesion is underscored by the uniformity of its constituent stromal cells, and their lack of nuclear atypia. Characterization by immunohistochemistry is helpful distinguishing Cellular angiofibroma from other mesenchymal lesions.

CASE PRESENTATION

We report the case of a 37-year-old woman, presenting with a painless nodule involving the vulva. This lesion had gradually increased in size; a simple excision was performed, and follow up was unremarkable. Gross examination showed a well circumscribed, firm tumor measuring 3× 3 × 2,5 cm. Histologically, the tumor was composed of uniform, short spindle-shaped cells, proliferating in an edematous to fibrous stroma and numerous small to medium-sized thick-walled vessels. A panel of immunohistochemical stains was performed, and confirmed the diagnosis of Cellular angiofibroma.

CONCLUSION

In this report we aim to describe the clinical, pathological and immunohistochemical features of this rare entity through a literature review, and to discuss other vulvar mesenchymal lesions.

Myoepithelioma-like Tumors of the Vulvar Region: A Distinctive Group of SMARCB1-deficient Neoplasms

We describe 9 tumors that resemble soft tissue myoepitheliomas but possess certain traits that do not fit perfectly into this category. These tumors, herein referred to as "myoepithelioma-like tumors of the vulvar region," occurred in the subcutis of the vulva and surrounding regions of adult women aged 24 to 65 years. Histologically, the tumors measured 2 to 7.7 cm and were well circumscribed, focally encapsulated, and lobulated. Tumor cells had an epithelioid to spindled shape, with fine amphophilic cytoplasm, and uniform nuclei with vesicular chromatin and nucleoli. The tumor stroma was relatively hypervascular, and comprised a mixture of myxoid and nonmyxoid components. Myxoid areas accounted for <5% to 95% of the tumor volume, wherein cells proliferated singly or in a loosely cohesive manner. In nonmyxoid areas, tumors cells grew in diffuse sheets or storiform arrangements. Immunohistochemically, all tested tumors were positive for vimentin, epithelial membrane antigen, and estrogen receptor; most tumors expressed actin. All tumors were negative for S100 protein, glial fibrillary acidic protein, and CD34. Cytokeratin expression was absent in all but 2 tumors, which showed rare positivity. SMARCB1 expression was deficient in all cases. EWSR1, FUS, and NR4A3 rearrangements were absent. All tumors were treated through surgery. Although 3 tumors regrew or recurred after intralesional excision, all 9 patients were alive without metastases at a mean follow-up of 66 months. Myoepithelioma-like tumors of the vulvar region constitute a distinct group of tumors, although future research is required to determine whether they are an unusual subtype of soft tissue myoepitheliomas or a separate disease.

Cellular angiofibroma in women: a review of the literature

Cellular Angiofibroma (CA) represents a quite recently described mesenchymal tumour that occurs in both genders, in particular in the vulvo-vaginal region in women and in the inguino-scrotal area in men. The first description of this tumour dates from Nucci et al. article in 1997; since then, the literature reports different reviews and case report of this tumour in both genders, but no article specifically addressing CA treatment and follow-up in women. In this review we collected all 79 published female CA cases, analyzing the clinical, pathological and immunohistochemical features of the tumour.

CA affects women mostly during the fifth decade of life, it is generally a small and asymptomatic mass that mainly arises in the vulvo-vaginal region, although there are reported pelvic and extra-pelvic cases. The treatment requires a simple local excision due to an extremely low ability to recurrent locally and no chance to metastasize. Throughout the immunohistochemical and pathological findings it is also easily possible a differential diagnosis from the other soft tissue tumours which affect the vulvo-vaginal area, such as spindle cell lipoma, solitary fibrous tumour, angiomyofibroblastoma and aggressive angiomyxoma.

Genital soft tissue tumors

Mesenchymal neoplasms of the vulvovaginal and inguinoscrotal regions are among the most diagnostically challenging specimens in the pathology laboratory owing largely to their unique intersection between general soft tissue tumors and relatively genital-specific mesenchymal tumors. Genital stromal tumors are a unique subset of soft tissue tumors encountered at this location, and this group includes fibroepithelial stromal polyp, superficial (cervicovaginal) myofibroblastoma, cellular angiofibroma, mammary-type myofibroblastoma, angiomyofibroblastoma and aggressive angiomyxoma. Aside from the striking morphologic and immunophenotypic similarity that is seen with these entities, there is evidence that a subset of genital stromal tumors may be linked genetically. This review will focus on simplifying this group of tumors and provide the pathologist or dermatopathologist with practical management information. Smooth muscle tumors of the external genitalia will also be discussed.

Coxalgia? Call the gynecologist

Cellular angiofibroma is a rare mesenchymal tumor that usually affects the vulvar region. It is commonly asymptomatic and treated with radical excision. We describe the first case of cellular angiofibroma located in the retroperitoneum presenting with coxalgia and laparoscopically treated. At the 6-month follow-up, the patient was coxalgia and disease free. Coxalgia is an unusual symptom for gynecologists; nevertheless, it is possible that several neoplasms may originate in the female pelvis, so any symptom requires careful evaluation. The laparoscopic approach may be effective in removing cellular angiofibroma, avoiding injuries to surrounding structures and unesthetic scarring and leading to a faster recovery.

WHO classification of soft tissue tumours: an update based on the 2013 (4th) edition

The fourth edition of the World Health Organization (WHO) Classification of Tumours of Soft Tissue and Bone was published in February 2013, and serves to provide an updated classification scheme and reproducible diagnostic criteria for pathologists. Given the relative rarity of soft tissue tumours and the rapid rate of immunohistochemical and genetic/molecular developments (not infrequently facilitating recognition of new tumour entities), this updated text edited by a consensus group is important for both practising pathologists and oncologists. The 2013 WHO classification includes several changes in soft tissue tumour classification, including several new entities (e.g., pseudomyogenic haemangioendothelioma, haemosiderotic fibrolipomatous tumour, and acral fibromyxoma), three newly included sections for gastrointestinal stromal tumours, nerve sheath tumours, and undifferentiated/unclassified soft tissue tumours, respectively, various 'reclassified' tumours, and a plethora of new genetic and molecular data for established tumour types that facilitate better definition and are useful as diagnostic tools. This article briefly outlines these updates based on the 2013 WHO classification of soft tissue tumours.

A large cellular angiofibroma of the male pelvis presenting with obstructive voiding: A case report and review of the literature

Cellular angiofibromas (CAF) are rare, benign soft-tissue tumours. The diagnosis of CAF is important given the heavy resemblance to other tumours. Herein, we describe a case of a rapidly growing, very large (13.5 cm) CAF located in the deep pelvis of a middle-aged male who presented with difficulty voiding.

Paratesticular cellular angiofibroma with atypical (bizarre) cells: case report and literature review

We report the extremely unusual occurrence of a cellular angiofibroma (CAF) with atypical (bizarre) cells in the spermatic cord. We present a 63-year-old man, who was referred to the Urology Service with a six-month history of a slowly growing painless nodule in the right inguino-scrotal area. The clinical impression was that of a lipoma. The mass was locally excised. Gross examination showed a well-circumscribed neoplasm attached to the spermatic cord and measuring 5cm in the greatest dimension. Microscopic examination of the tumor showed the appearance of CAF with scattered severely atypical (bizarre) cells distributed throughout the lesion. By immunohistochemistry, atypical cells showed diffuse expression of p16, CDK-4, CD34 and vimentin. Keratin AE1/AE3, S-100 protein, p53, and epithelial membrane antigen were negative. The patient is free of disease two months after tumor excision. To the best of our knowledge, this is the third case of CAF with atypical (bizarre) cells occurring in the paratesticular area. Pathologists should be aware of this morphological variation of CAF to avoid misdiagnosis and over-treatment.